Icycle spears. Selicy has four spears made of pure magical ice that won't melt even under the strongest heat that she can control at will. This spears won't dissapear and can still be controlled when inside an anti magic field

Hailstorm amulet. Once per battle Selicy will activate this amulet which will create an area of 60ft. diameter centered around herself. At the end of selicy's turn all creatures within the the area must succeed on a DC 16 constitution saving throw or receive 6d6 cold damage and are chilled until the end of their next turn. This area will stay active until Selicy is defeated or somehow the amulet get 30 ft. or further away from her ending the effect instantly

Selicy's scarf. The first time Selicy's health drops below 25% She gets +5 on all damage rolls and casts haste on herself

Multiattack. Selicy Can use two of her attacks every turn

Ice spears. Melee Weapon Attack: +9 to hit, reach 5 ft., 1 target. Hit: 34 (4d8 + 4) cold damage. 

spear throw. Ranged Weapon Attack: +9 to hit, range 30/60 ft., up to 4 targets. Hit: 9 (1d8 + 4) piercing damage. Whether this attack hits or misses the weapons returns to the user

Ice cross. This attack covers two perpendicular lines centered on a target, anyone within the path of the attack must make a DC 17 dexterity saving throw or receive 1d12+4 piercing damage or 2d12+8 if in the intersection. On a save receive no damage. The lines covered by the attack cannot be diagonal

Spear blast (recharge 4-6). As a bonus action Selicy can leave the thrown ice spear on the ground instead of it returning to its owner, then she teleports to the location of each spear and creates a 15ft radius cylinder, any creature must succeed on a DC 19 constitution saving throw or receive 2d10 cold damage, on a successful save receive half damage. This feature can only be used after selicy's health drops below half

Returning icycle. If the ice cross attack misses the target in the intersection Selicy can Repeat the attack on the same lines once.